Collagen glucosyltransferase will be purified to homogeneity from platelets and plasma and the binding of these enzymes to collagen studies will be used to produce antibodies for ultrastructural studies. BIBLIOGRAPHIC REFERENCES: A. Jamieson, Biochemical Events in Platelet Collagen Adhesion, in S. Sherry and A. Scribane (Eds), Platelets and Thrombosis, University Park Press, Baltimore, pp. 139-1480(1974). A. Jamieson, Interaction of Platelets and Collagen, in M. G. Baldini and S. Ebbe (Eds), Platelets: Production, Function, Transfusion and Storage, Grune and Stratton, Inc., New York, pp. 171-175(1974).